Nuclear is a scary word. Shrouded in mystery and misconception, it has captured the minds of scientists, politicians, activists and tyrants. The word still conjures up the worst images and ideas that humankind has to offer, even though we are in some way indebted to nuclear energy whether it is something so local such as powering our homes or something on a massive scale like our existence on this planet. A nuclear reaction is the starting block for human life in the core of a star and yet a nuclear reaction also has the power to take the lives of millions. I am in awe of this word.
Next month we will be r
emembering the 25th anniversary of the Chernobyl accident. A partial meltdown of the reactor core at the plant occurred, leading to an explosion of the core causing plumes of irradiated smoke and ash to smother a large area around the Ukraine, Belarus and Russia. Although disputed, over 50 people were killed as a direct result of the accident. However, the total number of people affected by the fallout from the accident is believed to be anywhere from 20,000 to 1million. We have also been witness to the recent nuclear crisis at the Fukushima plant in Japan in the aftermath of the earthquake on March 11th. Because of this, there is much political stigma and divided opinion over whether nuclear is a viable option and the debate has once again reached a head. Do the potential dangers, waste and legacy left from these power plants outweigh the colossal amounts of power that could be generated from nuclear fuel?
Before plunging head first into the debate, I think it is important to know some facts about Nuclear energy and why it is used. Firstly, we have to look at the current state of the energy industry, and our reliance on fossil fuels such as oil, coal and gas. In the UK alone, there are around 70 fossil fuel power stations currently operating, providing the majority of the UKs power. Only 7 Nuclear reactors are currently operating, and renewable energy such as wind turbines, tidal power and biomass only provides a tiny fraction of the power that fossil fuel reactors are capable. We are so reliant, in fact, that should all fossil reactors be shut down we would need to construct roughly 30 more nuclear reactors operating at around 2000MW to meet the current power requirements.
A recent study from scientists at the Oil Depletion Analysis Centre in London believes that our oil production will have reached a peak this year. As known reserves of oil begin to dry up, there will be a race between the major companies to claim what little oil there is left, thus increasing the rate of depletion even further. Within the next 15-20 years, there will be very little, if any, oil left. In order to preserve the precious black gold, we need to look elsewhere when it comes to fuelling power plants. Coal is simply out of the question now; the amount of waste and harmful gasses produced from the coal fired plant severely damages the atmosphere and health of anyone unfortunate enough to be living near one. And since our natural gas reserves are being depleted and even used for oil extraction, we are realistically left with two options; Renewable energy, and nuclear.
We all know how wind turbines, hydroelectricity and biomass works. And we know that unfortunately the amount of power produced from these methods is significantly less than the power produced from fossil fuels. However, there is much misconception and mystery surrounding nuclear energy. A number of people I have spoken to have absolutely no idea how power can be produced from nuclear fuel or what happens in the event of a meltdown. It is this uncertainty, as it has been prevalent during the ongoing Fukushima crisis that polarizes the debate between pro and anti nuclear preference.
Nuclear fission is the process that extracts energy from a heavy and naturally fissile element, such as uranium. In order to do this, you must breakdown the nucleus of the atom by bombarding it with a smaller sub atomic particle, causing the nucleus to change. When the nucleus of a uranium atom splits, it produces a lot of thermal energy. This energy can be used to heat water to create steam, and ultimately power a turbine to create electricity. A nuclear reaction is a chain reaction; once it starts you cannot stop it altogether, you can only control it. As the reaction progresses over time, more heat is produced and more radioactive elements are emitted so it is important to regulate this by keeping the overall temperature down using water as a coolant. Control rods made from boron are used to ‘interfere’ with the reaction. Boron absorbs the neutrons emitted from the uranium, helping to control the reaction. However, it will not keep the temperature of the reactor down. If the uranium rods are exposed to air, they react faster and produce more heat which is why it is so important to keep the rods submerged at all times. Should the cooling process be compromised, you could potentially end up with a meltdown.
Imagine filling and boiling a kettle for a cup of coffee. The element inside the kettle reaches a certain temperature and then cuts out, leaving you with boiling water and steam. This temperature is regulated to a degree by the water inside; should you boil the kettle continually with no water, then the element inside will burn through the plastic case of the kettle. Replace the element of the kettle with uranium rods and the plastic cover with steel reinforced concrete and the same process will happen on a grander scale. This is a meltdown; it is not a nuclear explosion however it is just as dangerous. Explosions at nuclear plants are caused by a build up of pressure within the core. This is usually vented harmlessly into the atmosphere. However, if the uranium rods are exposed to air, there will be a build up of hydrogen inside the core. If large quantities of hydrogen react with oxygen in the air, it will explode so venting this becomes very dangerous. A steam explosion could occur, rupturing the outer containment of the reactor and the reactor building. However, this could prevent a total meltdown of the core, as we have witnessed at the Fukushima plant.
With regards to the current Fukushima incident, the facts are continually shown to us through the news and there is a continual comparison with the Chernobyl accident that seems to be causing so much uncertainty. Of course there is always the possibility of a meltdown; it should never be ruled out. However, the public seem more glued to the screens and the blanket coverage of the crisis rather than taking it upon themselves to do the research. Dr Josef Oehman, a scientist working with MIT in the US, has posted a thread online explaining why he believes the reactor will not meltdown in a Chernobyl style incident, and how the radiation currently emitted from the damaged reactor will not be harmful to humans, since the majority of radioactive elements released including the noble gasses decay within seconds. Other scientists are more concerned, saying that so long as fuel rods are exposed to air there is always a potential for a meltdown. We know that the pool surrounding the old rods are drying up, but the Japanese authorities are doing everything they can to keep water levels at reasonable levels.
But what the public are failing to understand above all is that this is a crisis caused by an enormous earthquake and tsunami; a freak weather event that knocked out the auxiliary power systems that meant coolant could not flow to the reactor. A chain of unfortunate events led to the disaster that under normal working conditions would never have happened. The majority of Japan’s power plants use nuclear fuel, and no other plant has been in trouble to the same extent as the one at Fukushima. So perhaps there is an argument when it comes to building reactors in volatile regions. The one thing that has been most troubling with this incident, however, is the ineptitude of the Japanese authorities communicating with the power companies and the international community. Across the Pacific, US pharmacists are running low on iodine tablets as the public believe that the radioactive particles from the plant will actually affect them. And in China, stocks of salt tablets are running low as the public are misinformed that this will protect you from radiation sickness. The record must be set straight.
This confliction in theory undermines the facts and leads to uncertainty, so the public tend to take a cautious view when thinking about nuclear power. I believe that nuclear should not be used as a long term solution to our problems; however it really is the only viable option alongside renewable energy in the short term. Cynics will argue that the power companies operating the plants are deliberately withholding information when it comes to renewable sources in order to make more money. However, there is so much money in renewable energy, with solar panels, small wind turbines and biomass fuel that it is economically and environmentally more friendly for the consumer, and the corporations. But we need nuclear to power our infrastructure while the changes are made; changes such as new homes being built with the ability to produce their own energy from renewable sources.
While many people will disagree with my stance on nuclear energy, particularly while events in Japan continue to unfold, most would agree that there needs to be more clarity and understanding when it comes to nuclear energy. If you want to read the thread from Dr Josef Oehman, you can read it here: http://bravenewclimate.com/2011/03/13/fukushima-simple-explanation/
